blob: 577671c55153d4474f00b7f862ae2e97dff0b6ae [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_INIT_H
2#define _LINUX_INIT_H
3
Linus Torvalds1da177e2005-04-16 15:20:36 -07004#include <linux/compiler.h>
5
6/* These macros are used to mark some functions or
7 * initialized data (doesn't apply to uninitialized data)
8 * as `initialization' functions. The kernel can take this
9 * as hint that the function is used only during the initialization
10 * phase and free up used memory resources after
11 *
12 * Usage:
13 * For functions:
14 *
15 * You should add __init immediately before the function name, like:
16 *
17 * static void __init initme(int x, int y)
18 * {
19 * extern int z; z = x * y;
20 * }
21 *
22 * If the function has a prototype somewhere, you can also add
23 * __init between closing brace of the prototype and semicolon:
24 *
25 * extern int initialize_foobar_device(int, int, int) __init;
26 *
27 * For initialized data:
28 * You should insert __initdata between the variable name and equal
29 * sign followed by value, e.g.:
30 *
31 * static int init_variable __initdata = 0;
Geert Uytterhoevenae52bb22009-06-16 15:34:19 -070032 * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 *
34 * Don't forget to initialize data not at file scope, i.e. within a function,
35 * as gcc otherwise puts the data into the bss section and not into the init
36 * section.
37 *
38 * Also note, that this data cannot be "const".
39 */
40
41/* These are for everybody (although not all archs will actually
42 discard it in modules) */
Steven Rostedtfed19392008-08-14 22:47:19 -040043#define __init __section(.init.text) __cold notrace
Sam Ravnborgf3fe8662008-01-20 18:54:48 +010044#define __initdata __section(.init.data)
Sam Ravnborg37c514e2008-02-19 21:00:18 +010045#define __initconst __section(.init.rodata)
Sam Ravnborgf3fe8662008-01-20 18:54:48 +010046#define __exitdata __section(.exit.data)
Adrian Bunk3ff6eec2008-01-24 22:16:20 +010047#define __exit_call __used __section(.exitcall.exit)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020049/*
50 * modpost check for section mismatches during the kernel build.
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020051 * A section mismatch happens when there are references from a
52 * code or data section to an init section (both code or data).
53 * The init sections are (for most archs) discarded by the kernel
54 * when early init has completed so all such references are potential bugs.
55 * For exit sections the same issue exists.
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020056 *
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020057 * The following markers are used for the cases where the reference to
Sam Ravnborg312b1482008-01-28 20:21:15 +010058 * the *init / *exit section (code or data) is valid and will teach
Michal Nazarewicz5ea08172010-08-12 17:43:56 +020059 * modpost not to issue a warning. Intended semantics is that a code or
60 * data tagged __ref* can reference code or data from init section without
61 * producing a warning (of course, no warning does not mean code is
62 * correct, so optimally document why the __ref is needed and why it's OK).
63 *
64 * The markers follow same syntax rules as __init / __initdata.
65 */
Sam Ravnborg312b1482008-01-28 20:21:15 +010066#define __ref __section(.ref.text) noinline
67#define __refdata __section(.ref.data)
68#define __refconst __section(.ref.rodata)
69
Sam Ravnborg312b1482008-01-28 20:21:15 +010070/* compatibility defines */
71#define __init_refok __ref
72#define __initdata_refok __refdata
73#define __exit_refok __ref
74
Sam Ravnborg0e0d3142007-05-17 20:14:48 +020075
Linus Torvalds1da177e2005-04-16 15:20:36 -070076#ifdef MODULE
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010077#define __exitused
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#else
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010079#define __exitused __used
Linus Torvalds1da177e2005-04-16 15:20:36 -070080#endif
81
Sam Ravnborgeb8f6892008-01-20 20:07:28 +010082#define __exit __section(.exit.text) __exitused __cold
83
84/* Used for HOTPLUG */
85#define __devinit __section(.devinit.text) __cold
86#define __devinitdata __section(.devinit.data)
87#define __devinitconst __section(.devinit.rodata)
88#define __devexit __section(.devexit.text) __exitused __cold
89#define __devexitdata __section(.devexit.data)
90#define __devexitconst __section(.devexit.rodata)
91
92/* Used for HOTPLUG_CPU */
93#define __cpuinit __section(.cpuinit.text) __cold
94#define __cpuinitdata __section(.cpuinit.data)
95#define __cpuinitconst __section(.cpuinit.rodata)
96#define __cpuexit __section(.cpuexit.text) __exitused __cold
97#define __cpuexitdata __section(.cpuexit.data)
98#define __cpuexitconst __section(.cpuexit.rodata)
99
100/* Used for MEMORY_HOTPLUG */
101#define __meminit __section(.meminit.text) __cold
102#define __meminitdata __section(.meminit.data)
103#define __meminitconst __section(.meminit.rodata)
104#define __memexit __section(.memexit.text) __exitused __cold
105#define __memexitdata __section(.memexit.data)
106#define __memexitconst __section(.memexit.rodata)
107
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108/* For assembly routines */
Sam Ravnborg7923f902009-06-14 22:10:41 +0200109#define __HEAD .section ".head.text","ax"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110#define __INIT .section ".init.text","ax"
Prarit Bhargava86c0baf2007-05-02 19:27:05 +0200111#define __FINIT .previous
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100112
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100113#define __INITDATA .section ".init.data","aw",%progbits
114#define __INITRODATA .section ".init.rodata","a",%progbits
Ingo Molnar9f9975a2008-02-06 22:39:45 +0100115#define __FINITDATA .previous
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100117#define __DEVINIT .section ".devinit.text", "ax"
118#define __DEVINITDATA .section ".devinit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700119#define __DEVINITRODATA .section ".devinit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100120
121#define __CPUINIT .section ".cpuinit.text", "ax"
122#define __CPUINITDATA .section ".cpuinit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700123#define __CPUINITRODATA .section ".cpuinit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100124
125#define __MEMINIT .section ".meminit.text", "ax"
126#define __MEMINITDATA .section ".meminit.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700127#define __MEMINITRODATA .section ".meminit.rodata", "a"
Sam Ravnborgeb8f6892008-01-20 20:07:28 +0100128
Sam Ravnborg312b1482008-01-28 20:21:15 +0100129/* silence warnings when references are OK */
130#define __REF .section ".ref.text", "ax"
131#define __REFDATA .section ".ref.data", "aw"
Jan Beulich3f5e26c2008-10-25 15:02:51 -0700132#define __REFCONST .section ".ref.rodata", "a"
Sam Ravnborg312b1482008-01-28 20:21:15 +0100133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134#ifndef __ASSEMBLY__
135/*
136 * Used for initialization calls..
137 */
138typedef int (*initcall_t)(void);
139typedef void (*exitcall_t)(void);
140
141extern initcall_t __con_initcall_start[], __con_initcall_end[];
142extern initcall_t __security_initcall_start[], __security_initcall_end[];
143
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700144/* Used for contructor calls. */
145typedef void (*ctor_fn_t)(void);
146
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147/* Defined in init/main.c */
Arjan van de Ven59f94152008-07-30 12:49:02 -0700148extern int do_one_initcall(initcall_t fn);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800149extern char __initdata boot_command_line[];
150extern char *saved_command_line;
Vivek Goyal7e962872006-09-27 01:50:44 -0700151extern unsigned int reset_devices;
Adrian Bunk77d47582006-03-25 03:07:39 -0800152
153/* used by init/main.c */
Adrian Bunk46595392007-05-08 00:24:47 -0700154void setup_arch(char **);
155void prepare_namespace(void);
Adrian Bunk77d47582006-03-25 03:07:39 -0800156
Adrian Bunk7d195a52008-04-29 00:59:18 -0700157extern void (*late_time_init)(void);
158
Arjan van de Venf2511772009-12-13 20:29:01 +0100159extern int initcall_debug;
160
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161#endif
162
163#ifndef MODULE
164
165#ifndef __ASSEMBLY__
166
167/* initcalls are now grouped by functionality into separate
168 * subsections. Ordering inside the subsections is determined
169 * by link order.
170 * For backwards compatibility, initcall() puts the call in
171 * the device init subsection.
Andrew Morton735a7ff2006-10-27 11:42:37 -0700172 *
173 * The `id' arg to __define_initcall() is needed so that multiple initcalls
174 * can point at the same handler without causing duplicate-symbol build errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 */
176
Andrew Morton735a7ff2006-10-27 11:42:37 -0700177#define __define_initcall(level,fn,id) \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100178 static initcall_t __initcall_##fn##id __used \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 __attribute__((__section__(".initcall" level ".init"))) = fn
180
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800181/*
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700182 * Early initcalls run before initializing SMP.
183 *
184 * Only for built-in code, not modules.
185 */
186#define early_initcall(fn) __define_initcall("early",fn,early)
187
188/*
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800189 * A "pure" initcall has no dependencies on anything else, and purely
190 * initializes variables that couldn't be statically initialized.
191 *
192 * This only exists for built-in code, not for modules.
193 */
Michael Buesch73dd1162007-07-31 00:38:54 -0700194#define pure_initcall(fn) __define_initcall("0",fn,0)
Linus Torvaldsb3438f82006-11-20 11:47:18 -0800195
Andrew Morton735a7ff2006-10-27 11:42:37 -0700196#define core_initcall(fn) __define_initcall("1",fn,1)
197#define core_initcall_sync(fn) __define_initcall("1s",fn,1s)
198#define postcore_initcall(fn) __define_initcall("2",fn,2)
199#define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s)
200#define arch_initcall(fn) __define_initcall("3",fn,3)
201#define arch_initcall_sync(fn) __define_initcall("3s",fn,3s)
202#define subsys_initcall(fn) __define_initcall("4",fn,4)
203#define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s)
204#define fs_initcall(fn) __define_initcall("5",fn,5)
205#define fs_initcall_sync(fn) __define_initcall("5s",fn,5s)
Linus Torvalds8d610dd2006-12-11 12:12:04 -0800206#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs)
Andrew Morton735a7ff2006-10-27 11:42:37 -0700207#define device_initcall(fn) __define_initcall("6",fn,6)
208#define device_initcall_sync(fn) __define_initcall("6s",fn,6s)
209#define late_initcall(fn) __define_initcall("7",fn,7)
210#define late_initcall_sync(fn) __define_initcall("7s",fn,7s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
212#define __initcall(fn) device_initcall(fn)
213
214#define __exitcall(fn) \
215 static exitcall_t __exitcall_##fn __exit_call = fn
216
217#define console_initcall(fn) \
218 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100219 __used __section(.con_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221#define security_initcall(fn) \
222 static initcall_t __initcall_##fn \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100223 __used __section(.security_initcall.init) = fn
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
225struct obs_kernel_param {
226 const char *str;
227 int (*setup_func)(char *);
228 int early;
229};
230
231/*
232 * Only for really core code. See moduleparam.h for the normal way.
233 *
234 * Force the alignment so the compiler doesn't space elements of the
235 * obs_kernel_param "array" too far apart in .init.setup.
236 */
237#define __setup_param(str, unique_id, fn, early) \
Jan Beulichfd6c3a82009-03-12 10:58:33 +0000238 static const char __setup_str_##unique_id[] __initconst \
239 __aligned(1) = str; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 static struct obs_kernel_param __setup_##unique_id \
Adrian Bunk3ff6eec2008-01-24 22:16:20 +0100241 __used __section(.init.setup) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 __attribute__((aligned((sizeof(long))))) \
243 = { __setup_str_##unique_id, fn, early }
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245#define __setup(str, fn) \
246 __setup_param(str, fn, fn, 0)
247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
249 * returns non-zero. */
250#define early_param(str, fn) \
251 __setup_param(str, fn, fn, 1)
252
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800253/* Relies on boot_command_line being set */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254void __init parse_early_param(void);
Magnus Damm13977092009-03-30 14:37:25 -0700255void __init parse_early_options(char *cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256#endif /* __ASSEMBLY__ */
257
258/**
259 * module_init() - driver initialization entry point
260 * @x: function to be run at kernel boot time or module insertion
261 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800262 * module_init() will either be called during do_initcalls() (if
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 * builtin) or at module insertion time (if a module). There can only
264 * be one per module.
265 */
266#define module_init(x) __initcall(x);
267
268/**
269 * module_exit() - driver exit entry point
270 * @x: function to be run when driver is removed
271 *
272 * module_exit() will wrap the driver clean-up code
273 * with cleanup_module() when used with rmmod when
274 * the driver is a module. If the driver is statically
275 * compiled into the kernel, module_exit() has no effect.
276 * There can only be one per module.
277 */
278#define module_exit(x) __exitcall(x);
279
280#else /* MODULE */
281
282/* Don't use these in modules, but some people do... */
Borislav Petkov329bd412009-10-02 15:23:21 +0200283#define early_initcall(fn) module_init(fn)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284#define core_initcall(fn) module_init(fn)
285#define postcore_initcall(fn) module_init(fn)
286#define arch_initcall(fn) module_init(fn)
287#define subsys_initcall(fn) module_init(fn)
288#define fs_initcall(fn) module_init(fn)
289#define device_initcall(fn) module_init(fn)
290#define late_initcall(fn) module_init(fn)
291
292#define security_initcall(fn) module_init(fn)
293
Robert P. J. Day4500d062008-07-25 01:45:49 -0700294/* Each module must use one module_init(). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295#define module_init(initfn) \
296 static inline initcall_t __inittest(void) \
297 { return initfn; } \
298 int init_module(void) __attribute__((alias(#initfn)));
299
300/* This is only required if you want to be unloadable. */
301#define module_exit(exitfn) \
302 static inline exitcall_t __exittest(void) \
303 { return exitfn; } \
304 void cleanup_module(void) __attribute__((alias(#exitfn)));
305
306#define __setup_param(str, unique_id, fn) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307#define __setup(str, func) /* nothing */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308#endif
309
Johannes Bergab3bfca2007-05-06 14:50:49 -0700310/* Data marked not to be saved by software suspend */
Denys Vlasenko07b3bb12010-02-20 01:03:52 +0100311#define __nosavedata __section(.data..nosave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
313/* This means "can be init if no module support, otherwise module load
314 may call it." */
315#ifdef CONFIG_MODULES
316#define __init_or_module
317#define __initdata_or_module
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100318#define __initconst_or_module
319#define __INIT_OR_MODULE .text
320#define __INITDATA_OR_MODULE .data
321#define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322#else
323#define __init_or_module __init
324#define __initdata_or_module __initdata
Jan Beulich8b5a10f2009-08-19 08:40:48 +0100325#define __initconst_or_module __initconst
326#define __INIT_OR_MODULE __INIT
327#define __INITDATA_OR_MODULE __INITDATA
328#define __INITRODATA_OR_MODULE __INITRODATA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329#endif /*CONFIG_MODULES*/
330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331/* Functions marked as __devexit may be discarded at kernel link time, depending
332 on config options. Newer versions of binutils detect references from
333 retained sections to discarded sections and flag an error. Pointers to
334 __devexit functions must use __devexit_p(function_name), the wrapper will
335 insert either the function_name or NULL, depending on the config options.
336 */
337#if defined(MODULE) || defined(CONFIG_HOTPLUG)
338#define __devexit_p(x) x
339#else
340#define __devexit_p(x) NULL
341#endif
342
343#ifdef MODULE
344#define __exit_p(x) x
345#else
346#define __exit_p(x) NULL
347#endif
348
349#endif /* _LINUX_INIT_H */